CN104079318A - Multiple narrowband interference suppression method for ultra-broadband communication system based on non-linear Chirp pulses - Google Patents

Abstract

The invention provides a multiple narrowband interference suppression method for an ultra-broadband communication system based on non-linear Chirp pulses, and belongs to the technical field of wireless communication. The system comprises an information source node and a destination node. According to the method, frequency domain parameters of narrowband interference are obtained according to the spectrum sensing technology, time domain processing is conducted on a waveform according to the good time frequency mapping relation of the Chirp pulses, and therefore corresponding frequency domain characteristics are changed, and one kind of self-adaptive non-linear Chirp ultra-broadband pulses is designed for suppressing multiple narrowband interference existing in the ultra-broadband system. The pulse waveform design scheme is suitable for the ultra-broadband communication system based on narrow pulses, and energy of the designed ultra-broadband pulses is distributed in the persistent period of the whole waveform, and the problem of high-peak power is solved. According to the method, the multiple narrowband interference in the ultra-broadband system is effectively suppressed, and the anti-interference capability and communication performance of the system are enhanced.

Description

The many narrow-band interference rejection methods of ultra-wideband communication system based on non-linear Chirp pulse

Technical field

The present invention relates to a kind of many narrow-band interference rejection methods of ultra broadband (UWB) communication system based on non-linear Chirp pulse, belong to wireless communication technology field.

Background technology

Ultra broadband (UWB) is a kind of lower powered short distance high-speed radiocommunication technology, it provides new thinking for solving the problem of radio spectrum resources scarcity, from FCC, since approval super-broadband tech in 2002 can be civilian, super-broadband tech has caused that academia and industrial quarters more and more pay close attention to.Super-broadband tech has bandwidth, transmission rate is high, the features such as low-power consumption, good confidentiality and anti-multipath fading, these features have broad application prospects super-broadband tech in the fields such as radio communication, radar, accurate location, especially in indoor short distance high-speed radiocommunication, have unrivaled advantage.

Narrowband interference problems is present in various system of broadband wireless communication, the distinguishing feature of radio ultra wide band system is exactly to use extremely wide frequency spectrum with sharing mode, and its signal transmission power is extremely low, for narrowband systems, the existence of UWB signal is only equivalent to improve background noise, and for UWB system, the existence with more superpower narrow band signal will inevitably produce serious interference to radio ultra wide band system, therefore must adopt Narrow Band Interference Suppression Technique to solve the spectral compatibility problem of radio ultra wide band system.C.Wang etc. are (referring to C.Wang, M.D.Ma, R.D.Ying and Y.H.Yang, " Narrowband Interference Mitigation in DS-UWB systems, " IEEE Signal Processing Letters, vol.17, no.5, pp.429-432,2010.) first the auxiliary interference mitigation technology of coding is incorporated in direct sequence spread spectrum radio ultra wide band system, propose a kind of novel frequency expansion sequence that suppresses arrowband interference, but obtained the calculating process complexity of this sequence.X.L.Shi is (referring to X.L.Shi, " Adaptive UWB Pulse design method for Multiple Narrowband Interference Suppression, " IEEE International Conference on Intelligent Computing and Intelligent Systems, pp.545-548, 2010.) cognitive radio technology is combined with Parks-McClellan algorithm, design and a kind ofly not only met FCC Emission Mask but also can suppress the self adaptation pulse that many arrowbands disturb, but be difficult to obtain the time-domain expression of pulse, thereby limited its practical application.(the S.Y.Xu such as S.Y.Xu, Z.Q.Bai, Q.H.Yang and K.S.Kwak, " Singular value decomposition-based algorithm for suppression of IEEE802.11a interference in multiple access TH-UWB systems, " Proceedings of 2nd International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CrownCom2007), pp.105-111, 2007.) proposed to utilize the method for singular value decomposition (SVD) to suppress the arrowband interference in radio ultra wide band system, the method is for almost not loss of useful signal, and do not need to obtain the detailed features that arrowband disturbs, but the complexity of this method is higher.

Because UWB system adopts burst pulse, carry out carry information, the type of burst pulse directly has influence on the power spectral density transmitting, and the optimal design of paired pulses power spectrum also can play the effect that arrowband disturbs that suppresses.Due to Chirp pulse, to have peak-to-average power ratio low, time-frequency domain corresponding relation is simple, the advantages such as Anti-interference Design is flexible, Z.Q.Bai etc. are (referring to Z.Q.Bai, X.T.Li, D.F.Yuan, and K.S.Kwak, " Non-linear chirp based UWB waveform design for suppression of NBI, " Wirel.Commun.Mob.Comput., issue6, vol.12, pp.545-552, Apr.2012.) adopt Chirp pulse to replace the burst pulse in traditional UWB system, employing disturbs centre frequency place to make the thought of the instantaneous frequency rate maximum of Chirp pulse in arrowband, design non-linear Chirp pulse and realize the inhibition that arrowband disturbs.H.B.Shen etc. are (referring to H.B.Shen, W.H.Zhang, and K.S.Kwak, " Modified chirp waveforms in cognitive UWB system; " in Proc.ICC Workshops ' 08, pp.504-507, May.2008.) adopt thought that frequency spectrum is evaded to design non-linear Chirp pulse to suppress arrowband and disturb.Said method all only needs to process and can change corresponding frequency domain characteristic through time domain, suppress the object that arrowband disturbs, but they has only considered the inhibition that single arrowband disturbs thereby reach.

Summary of the invention

According to the shortcoming and defect of prior art and solution, the invention provides a kind of many narrow-band interference rejection methods of ultra broadband (UWB) communication system based on non-linear Chirp pulse, by designing a class self-adaptation nonlinear Chirp ultra-short pulse, bring and suppress many arrowbands and disturb, to significantly improve the performance of communication system.

Technical scheme of the present invention is as follows:

A kind of many narrow-band interference rejection methods of ultra broadband (UWB) communication system based on non-linear Chirp pulse, by following system, realized, this system comprises information source node and the destination node of single antenna, information source node by additive white Gaussian noise channel to destination node broadcast singal; The signal that destination node receives comprises many narrow-band interference signals and the additive white Gaussian noise signal existing in the signal, channel circumstance of information source node transmitting, and the concrete steps of the method are as follows:

A, ultra-wideband communication system are prepared to start working;

B, ultra-wideband communication system obtain the corresponding frequency band (f at many narrow-band interference signals place in channel circumstance by frequency spectrum perception technology _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal, N is the number of narrow-band interference signal in communication environment;

The design that C, foundation provide, design can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively, is respectively Atan Chirp and Asinh Chirp;

D, employing pseudo random sequence c=(c (1), c (2) ..., c (l) ..., c (N _c)) as the direct sequence spread spectrum codes of system, wherein c (l) is l chip of spreading code, c (l) ∈ ± 1}, l ∈ (1,2 ..., N _c), N _cfor the length of spreading code, chip-spaced is T _c;

Chirp pulse after E, every bit are modulated by spreading code is characterized by b wherein _n{ ± 1} is n transmission data bit to ∈, and bit duration is N _ct _c, t represents the time, the single superwide band pulse wave of p (t) for sending adopts step C design to obtain, p (t-lT _c) represent that p (t) is along time shaft to right translation lT _cindividual unit, l ∈ (1,2 ..., N _c);

F, information source node send data bit, and by carrying out characterization data bit with ultra-broadband signal after band spectrum modulation, ultra-broadband signal is sent by its configuration antenna, signal arrives receiving terminal through additive white Gaussian noise channel, receiving terminal antenna reception to signal comprise the signal that the information source node that decayed sends, the narrow-band interference signal of introducing with many narrowband systems of UWB coexistence of systems in channel and the additive white Gaussian noise signal in channel;

G, at receiving terminal, adopt correlation receiver to receive signal, receiver is set up good synchronizeing with transmitter;

H, calculate the judgment variables of correlator output, the signal the receiving template signal v (t) corresponding to every bit carried out relevant, it exports judgment variables is Z, and Z includes and uses signal terms S, arrowband distracter I and white Gaussian noise item N _g;

I, employing maximum-likelihood criterion are adjudicated, and draw the Average Error Probabilities P of this system _eexpression formula be:

P _e＝P(Z ⁽¹⁾＜0)+P(Z ⁽⁰⁾＞0)

＝P((S ⁽¹⁾+I+N _G)＜0)+P((S ⁽⁰⁾+I+N _G)＞0)

Z wherein ⁽¹⁾the judgment variables of decision device output when representative sends data bit 1, P (Z ⁽¹⁾<0) represent that 1 misjudgement of transmission data bit is 0 probability, Z ⁽⁰⁾the judgment variables of decision device output when representative sends data bit 0, P (Z ⁽⁰⁾>0) represent that 0 misjudgement of transmission data bit is 1 probability, S ⁽¹⁾the useful signal item that when representative sends data bit 1, judgment variables comprises, S ⁽⁰⁾the useful signal item that when representative sends data bit 0, judgment variables comprises;

J, when information is sent, sign off;

Design in above-mentioned steps C can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively: Atan Chirp and Asinh Chirp, and specific design method step is as follows:

(1) based on Atan function and Asinh function, by the following method non-linear Chirp pulse is processed, obtain respectively Nonlinear A tan Chirp pulse and Asinh Chirp pulse;

(2) first by frequency spectrum perception technology, obtain the corresponding frequency band (f at interference place in many arrowbands in channel circumstance _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal;

(3) suppose that the ultra broadband spectral range that FCC stipulates is (f _l, f _h), f wherein _l=3.1GHz, f _h=10.6GHz removes the frequency band at interference place, N arrowband in Chirp pulse available band, and the frequency band of Chirp pulse becomes the bandwidth of Chirp pulse is $B^{\&prime;}=(f_h-f_l)-\underset{j=1}{\overset{N}{\&cup;}}(f_{\mathrm{ih}\left(j\right)}-f_{\mathrm{il}\left(j\right)}),$ Wherein symbol U is the meaning of union, represents in ultra broadband spectral range, to remove the frequency band of interference place, arrowband the union of residue frequency band;

(4) according to the time-frequency mapping relations of Chirp pulse, the frequency domain of narrow band signal is mapped to time domain, j the lower frequency limit f that arrowband disturbs _{il (j)}corresponding time point T _{fra (j)}=T (f _{il (j)}-f _l)/B ', j ∈ (1,2 ..., N), T is the Chirp pulse period, at time point T _{fra (j)}place disturbs N arrowband to remove, and makes the time-frequency corresponding relation of Chirp pulse as follows: (0, T _{fra (1)}) → (f _l, f _{il (1)}), (T _{fra (j)}, T _{fra (j+1)}) → (f _{ih (j)}, f _{il (j+1)}), j ∈ (1,2 ..., N-1) with (T _{fra (N)}, T) → (f _{ih (N)}, f _h), obtain the instantaneous frequency of non-linear Chirp pulse;

The instantaneous frequency of Atan Chirp pulse is:

$\begin{array}{c}{f}_{w1}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan \mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array},$

Gate function wherein $G_j\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(j\right)}<t\&le;T_{\mathrm{fra}(j+1)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ J ∈ (1,2 ..., N-1), gate function $G_N\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(N\right)}<t\&le;T\\ 0,& \mathrm{otherwise}\end{array}\right.,$ Gate function $G\left(t\right)=\left\{\begin{array}{cc}1,& 0\&le;t\&le;T_{\mathrm{fra}\left(1\right)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ α when Chirp waveform frequency scope is set, meets the parameter of narrow band signal time-frequency mapping relations, β=α (t/T _{fra (1)}-1), γ _j=α (t-T _{fra (j)})/(T _{fra (j+1)}-T _{fra (j)}), j ∈ (1,2 ..., N-1), γ _n=α (t-T _{fra (N)})/(T-T _{fra (N)}), symbol beta, γ _j, γ _nbe the intermediate symbols of getting in order to simplify the expression formula of instantaneous frequency, without concrete practical significance, only represent their equal sign formulas below separately, otherwise is the meaning of " other ", represents G _j(t), G _n(t) time outside the time restriction condition above right-hand member and in G (t) formula;

The instantaneous frequency of Asinh Chirp pulse is:

$\begin{array}{c}{f}_{w2}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}\mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array};$

(5) to instantaneous frequency integration, can obtain the time-domain expression of non-linear Chirp pulse;

The time-domain expression of Atan Chirp pulse is:

$\begin{array}{c}{p}_{w1}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w1}\left(x\right)=x\&CenterDot;\arctan x-\frac{\ln (1+x^2)}{2},$ X is function c _w1(x) independent variable;

The time-domain expression of Asinh Chirp pulse is:

$\begin{array}{c}{p}_{w2}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w2}\left(x\right)=x\&CenterDot;\mathrm{arcsinh}x-\sqrt{1+x^2}.$

Advantage of the present invention is as follows: the many Suppression of narrow band interference aspect from radio ultra wide band system is considered, by frequency spectrum perception technology, obtain the frequency domain parameter that arrowband disturbs, utilize the good time-frequency mapping relations of Chirp pulse, by time domain, process and change corresponding frequency domain characteristic, and can directly obtain the time-domain expression of waveform, flexible design, complexity is low; This class impulse waveform design is applicable to the ultra-wideband communication system based on burst pulse, its Energy distribution of designed ultra-wideband pulse within the duration of whole waveform, thereby avoided the problem of high-peak power.The non-linear Chirp pulse that the many arrowbands of Adaptive Suppression of the inventive method design disturb efficiently solves the many narrowband interference problems in ultra-wideband communication system, has significantly improved systematic function.

Accompanying drawing explanation

Fig. 1 is system model figure of the present invention, wherein: 1, information source node; 2, additive white Gaussian noise channel; 3, destination node.

Fig. 2 is the FB(flow block) of the inventive method, each step that wherein A-J is flow process.

Fig. 3 can suppress two kinds of non-linear Chirp pulse design method FB(flow block) that many arrowbands disturb adaptively in the inventive method step C, wherein (1)-(5) are its each step.

Fig. 4 is time domain waveform and the power spectral density analogous diagram that can suppress adaptively two kinds of non-linear Chirp pulses of many arrowbands interference of the present invention, wherein above two charts represent respectively the time domain waveform of two non-linear Chirp pulses, below two charts represent respectively the power spectral density analogous diagram of two non-linear Chirp pulses, in figure, (a) is Atan Chirp, (b) be Asinh Chirp, in emulation, considered that two arrowbands disturb, get N=2, as can be seen from the figure, designed pulse can effectively suppress two arrowbands interference.

Fig. 5 is ultra-wideband communication system bit error probability (BER) the performance simulation figure that the present invention is based on non-linear Chirp pulse, two arrowbands in emulation, have been considered, from analogous diagram, find out that the UWB systematic function based on Atan Chirp and Asinh Chirp pulse is better than the UWB systematic function based on conventional linear Chirp pulse, and the theoretical curve that approaches very much system (suppresses arrowband interference completely, system only has white Gaussian noise to disturb), therefore can draw: the ability that the Atan Chirp of the present invention's design and Asinh Chirp pulse suppress to disturb by many arrowbands is better than conventional linear Chirp pulse.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described, but be not limited to this.

Embodiment:

A kind of many narrow-band interference rejection methods of ultra broadband (UWB) communication system based on non-linear Chirp pulse, by following system, realized, as shown in Figure 1, this system comprises information source node 1 and the destination node 3 of single antenna, and information source node 1 is passed through additive white Gaussian noise channel 2 to destination node 3 broadcast singals; The signal that destination node 3 receives comprises many narrow-band interference signals and the additive white Gaussian noise signal existing in the signal, channel circumstance of information source node 1 transmitting, and as shown in Figure 2, the concrete steps of the method are as follows:

A, ultra-wideband communication system are prepared to start working;

B, ultra-wideband communication system obtain the corresponding frequency band (f at many narrow-band interference signals place in channel circumstance by frequency spectrum perception technology _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal, N is the number of narrow-band interference signal in communication environment;

The design that C, foundation provide, design can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively, is respectively Atan Chirp and Asinh Chirp;

D, employing pseudo random sequence c=(c (1), c (2) ..., c (l) ..., c (N _c)) as the direct sequence spread spectrum codes of system, wherein c (l) is l chip of spreading code, c (l) ∈ ± 1}, l ∈ (1,2 ..., N _c), N _cfor the length of spreading code, chip-spaced is T _c;

Chirp pulse after E, every bit are modulated by spreading code is characterized by b wherein _n{ ± 1} is n transmission data bit to ∈, and bit duration is N _ct _c, t represents the time, the single superwide band pulse wave of p (t) for sending adopts step C design to obtain, p (t-lT _c) represent that p (t) is along time shaft to right translation lT _cindividual unit, l ∈ (1,2 ..., N _c);

F, information source node send data bit, and by carrying out characterization data bit with ultra-broadband signal after band spectrum modulation, ultra-broadband signal is sent by its configuration antenna, signal arrives receiving terminal through additive white Gaussian noise channel, receiving terminal antenna reception to signal comprise the signal that the information source node that decayed sends, the narrow-band interference signal of introducing with many narrowband systems of UWB coexistence of systems in channel and the additive white Gaussian noise signal in channel;

G, at receiving terminal, adopt correlation receiver to receive signal, receiver is set up good synchronizeing with transmitter;

H, calculate the judgment variables of correlator output, the signal the receiving template signal v (t) corresponding to every bit carried out relevant, it exports judgment variables is Z, and Z includes and uses signal terms S, arrowband distracter I and white Gaussian noise item N _g;

I, employing maximum-likelihood criterion are adjudicated, and draw the Average Error Probabilities P of this system _eexpression formula be:

P _e＝P(Z ⁽¹⁾＜0)+P(Z ⁽⁰⁾＞0)

＝P((S ⁽¹⁾+I+N _G)＜0)+P((S ⁽⁰⁾+I+N _G)＞0)

Z wherein ⁽¹⁾the judgment variables of decision device output when representative sends data bit 1, P (Z ⁽¹⁾<0) represent that 1 misjudgement of transmission data bit is 0 probability, Z ⁽⁰⁾the judgment variables of decision device output when representative sends data bit 0, P (Z ⁽⁰⁾>0) represent that 0 misjudgement of transmission data bit is 1 probability, S ⁽¹⁾the useful signal item that when representative sends data bit 1, judgment variables comprises, S ⁽⁰⁾the useful signal item that when representative sends data bit 0, judgment variables comprises;

J, when information is sent, sign off;

Design in above-mentioned steps C can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively: Atan Chirp and Asinh Chirp, and specific design method step is as follows:

(1) based on Atan function and Asinh function, by the following method non-linear Chirp pulse is processed, obtain respectively Nonlinear A tan Chirp pulse and Asinh Chirp pulse;

(2) first by frequency spectrum perception technology, obtain the corresponding frequency band (f at interference place in many arrowbands in channel circumstance _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal;

(3) suppose that the ultra broadband spectral range that FCC stipulates is (f _l, f _h), f wherein _l=3.1GHz, f _h=10.6GHz removes the frequency band at interference place, N arrowband in Chirp pulse available band, and the frequency band of Chirp pulse becomes the bandwidth of Chirp pulse is $B^{\&prime;}=(f_h-f_l)-\underset{j=1}{\overset{N}{\&cup;}}(f_{\mathrm{ih}\left(j\right)}-f_{\mathrm{il}\left(j\right)}),$ Wherein symbol U is the meaning of union, represents in ultra broadband spectral range, to remove the frequency band of interference place, arrowband the union of residue frequency band;

(4) according to the time-frequency mapping relations of Chirp pulse, the frequency domain of narrow band signal is mapped to time domain, j the lower frequency limit f that arrowband disturbs _{il (j)}corresponding time point T _{fra (j)}=T (f _{il (j)}-fl)/B ', j ∈ (1,2 ..., N), T is the Chirp pulse period, at time point T _{fra (j)}place disturbs N arrowband to remove, and makes the time-frequency corresponding relation of Chirp pulse as follows: (0, T _{fra (1)}) → (f _l, f _{il (1)}), (T _{fra (j)}, T _{fra (j+1)}) → (f _{ih (j)}, f _{il (j+1)}), j ∈ (1,2 ..., N-1) with (T _{fra (N)}, T) → (f _{ih (N)}, f _h), obtain the instantaneous frequency of non-linear Chirp pulse;

The instantaneous frequency of Atan Chirp pulse is:

$\begin{array}{c}{f}_{w1}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan \mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array},$

Gate function wherein $G_j\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(j\right)}<t\&le;T_{\mathrm{fra}(j+1)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ J ∈ (1,2 ..., N-1), gate function $G_N\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(N\right)}<t\&le;T\\ 0,& \mathrm{otherwise}\end{array}\right.,$ Gate function $G\left(t\right)=\left\{\begin{array}{cc}1,& 0\&le;t\&le;T_{\mathrm{fra}\left(1\right)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ α when Chirp waveform frequency scope is set, meets the parameter of narrow band signal time-frequency mapping relations, β=α (t/T _{fra (1)}-1), γ _j=α (t-T _{fra (j)})/(T _{fra (j+1)}-T _{fra (j)}), j ∈ (1,2 ..., N-1), γ _n=α (t-T _{fra (N)})/(T-T _{fra (N)}), symbol beta, γ _j, γ _nbe the intermediate symbols of getting in order to simplify the expression formula of instantaneous frequency, without concrete practical significance, only represent their equal sign formulas below separately, otherwise is the meaning of " other ", represents G _j(t), G _n(t) time outside the time restriction condition above right-hand member and in G (t) formula;

The instantaneous frequency of Asinh Chirp pulse is:

$\begin{array}{c}{f}_{w2}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}\mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array};$

(5) to instantaneous frequency integration, can obtain the time-domain expression of non-linear Chirp pulse;

The time-domain expression of Atan Chirp pulse is:

$\begin{array}{c}{p}_{w1}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w1}\left(x\right)=x\&CenterDot;\arctan x-\frac{\ln (1+x^2)}{2},$ X is function c _w1(x) independent variable;

The time-domain expression of Asinh Chirp pulse is:

$\begin{array}{c}{p}_{w2}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w2}\left(x\right)=x\&CenterDot;\mathrm{arcsinh}x-\sqrt{1+x^2}.$

Claims (1)

1. many narrow-band interference rejection methods of the ultra-wideband communication system based on non-linear Chirp pulse, by following system, realized, this system comprises information source node and the destination node of single antenna, information source node by additive white Gaussian noise channel to destination node broadcast singal; The signal that destination node receives comprises many narrow-band interference signals and the additive white Gaussian noise signal existing in the signal, channel circumstance of information source node transmitting, and the concrete steps of the method are as follows:

A, ultra-wideband communication system are prepared to start working;

B, ultra-wideband communication system obtain the corresponding frequency band (f at many narrow-band interference signals place in channel circumstance by frequency spectrum perception technology _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal, N is the number of narrow-band interference signal in communication environment;

The design that C, foundation provide, design can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively, is respectively Atan Chirp and Asinh Chirp;

D, employing pseudo random sequence c=(c (1), c (2) ..., c (l) ..., c (N _c)) as the direct sequence spread spectrum codes of system, wherein c (l) is l chip of spreading code, c (l) ∈ ± 1}, l ∈ (1,2 ..., N _c), N _cfor the length of spreading code, chip-spaced is T _c;

Chirp pulse after E, every bit are modulated by spreading code is characterized by b wherein _n{ ± 1} is n transmission data bit to ∈, and bit duration is N _ct _c, t represents the time, the single superwide band pulse wave of p (t) for sending adopts step C design to obtain, p (t-lT _c) represent that p (t) is along time shaft to right translation lT _cindividual unit, l ∈ (1,2 ..., N _c);

F, information source node send data bit, and by carrying out characterization data bit with ultra-broadband signal after band spectrum modulation, ultra-broadband signal is sent by its configuration antenna, signal arrives receiving terminal through additive white Gaussian noise channel, receiving terminal antenna reception to signal comprise the signal that the information source node that decayed sends, the narrow-band interference signal of introducing with many narrowband systems of UWB coexistence of systems in channel and the additive white Gaussian noise signal in channel;

G, at receiving terminal, adopt correlation receiver to receive signal, receiver is set up good synchronizeing with transmitter;

H, calculate the judgment variables of correlator output, the signal the receiving template signal v (t) corresponding to every bit carried out relevant, it exports judgment variables is Z, and Z includes and uses signal terms S, arrowband distracter I and white Gaussian noise item N _g;

I, employing maximum-likelihood criterion are adjudicated, and draw the Average Error Probabilities P of this system _eexpression formula be:

P _e＝P(Z ⁽¹⁾＜0)+P(Z ⁽⁰⁾＞0)

＝P((S ⁽¹⁾+I+N _G)＜0)+P((S ⁽⁰⁾+I+N _G)＞0)

Z wherein ⁽¹⁾the judgment variables of decision device output when representative sends data bit 1, P (Z ⁽¹⁾<0) represent that 1 misjudgement of transmission data bit is 0 probability, Z ⁽⁰⁾the judgment variables of decision device output when representative sends data bit 0, P (Z ⁽⁰⁾>0) represent that 0 misjudgement of transmission data bit is 1 probability, S ⁽¹⁾the useful signal item that when representative sends data bit 1, judgment variables comprises, S ⁽⁰⁾the useful signal item that when representative sends data bit 0, judgment variables comprises;

J, when information is sent, sign off;

Design in above-mentioned steps C can suppress two kinds of non-linear Chirp pulses that many arrowbands disturb adaptively: Atan Chirp and Asinh Chirp, and specific design method step is as follows:

(1) based on Atan function and Asinh function, by the following method non-linear Chirp pulse is processed, obtain respectively Nonlinear A tan Chirp pulse and Asinh Chirp pulse;

(2) first by frequency spectrum perception technology, obtain the corresponding frequency band (f at interference place in many arrowbands in channel circumstance _{il (j)}, f _{ih (j)}) and centre frequency f _{i (j)}, j ∈ (1,2 ..., N), f _{il (j)}and f _{ih (j)}be respectively lower frequency limit and the upper limiting frequency of j narrow-band interference signal;

(3) suppose that the ultra broadband spectral range that FCC stipulates is (f _l, f _h), f wherein _l=3.1GHz, f _h=10.6GHz removes the frequency band at interference place, N arrowband in Chirp pulse available band, and the frequency band of Chirp pulse becomes the bandwidth of Chirp pulse is $B^{\&prime;}=(f_h-f_l)-\underset{j=1}{\overset{N}{\&cup;}}(f_{\mathrm{ih}\left(j\right)}-f_{\mathrm{il}\left(j\right)}),$ Wherein symbol U is the meaning of union, represents in ultra broadband spectral range, to remove the frequency band of interference place, arrowband the union of residue frequency band;

(4) according to the time-frequency mapping relations of Chirp pulse, the frequency domain of narrow band signal is mapped to time domain, j the lower frequency limit f that arrowband disturbs _{il (j)}corresponding time point T _{fra (j)}=T (f _{il (j)}-f _l)/B ', j ∈ (1,2 ..., N), T is the Chirp pulse period, at time point T _{fra (j)}place disturbs N arrowband to remove, and makes the time-frequency corresponding relation of Chirp pulse as follows: (0, T _{fra (1)}) → (f _l, f _{il (1)}), (T _{fra (j)}, T _{fra (j+1)}) → (f _{ih (j)}, f _{il (j+1)}), j ∈ (1,2 ..., N-1) with (T _{fra (N)}, T) → (f _{ih (N)}, f _h), obtain the instantaneous frequency of non-linear Chirp pulse;

The instantaneous frequency of Atan Chirp pulse is:

$\begin{array}{c}{f}_{w1}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan \mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;\arctan {\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array},$

Gate function wherein $G_j\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(j\right)}<t\&le;T_{\mathrm{fra}(j+1)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ J ∈ (1,2 ..., N-1), gate function $G_N\left(t\right)=\left\{\begin{array}{cc}1,& T_{\mathrm{fra}\left(N\right)}<t\&le;T\\ 0,& \mathrm{otherwise}\end{array}\right.,$ Gate function $G\left(t\right)=\left\{\begin{array}{cc}1,& 0\&le;t\&le;T_{\mathrm{fra}\left(1\right)}\\ 0,& \mathrm{otherwise}\end{array}\right.,$ α when Chirp waveform frequency scope is set, meets the parameter of narrow band signal time-frequency mapping relations, β=α (t/T _{fra (1)}-1), γ _j=α (t-T _{fra (j)})/(T _{fra (j+1)}-T _{fra (j)}), j ∈ (1,2 ..., N-1), γ _n=α (t-T _{fra (N)})/(T-T _{fra (N)}), symbol beta, γ _j, γ _nbe the intermediate symbols of getting in order to simplify the expression formula of instantaneous frequency, without concrete practical significance, only represent their equal sign formulas below separately, otherwise is the meaning of " other ", represents G _j(t), G _n(t) time outside the time restriction condition above right-hand member and in G (t) formula;

The instantaneous frequency of Asinh Chirp pulse is:

$\begin{array}{c}{f}_{w2}\left(t\right)=[f_{\mathrm{il}\left(1\right)}+\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}\mathrm{\&beta;}]\&CenterDot;G\left(t\right)+\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}[f_{\mathrm{ih}\left(j\right)}+\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_j]\&CenterDot;G_j\left(t\right)\\ +[f_{\mathrm{ih}\left(N\right)}+\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;\mathrm{arcsinh}{\mathrm{\&gamma;}}_N]\&CenterDot;G_N\left(t\right)\end{array};$

(5) to instantaneous frequency integration, can obtain the time-domain expression of non-linear Chirp pulse;

The time-domain expression of Atan Chirp pulse is:

$\begin{array}{c}{p}_{w1}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\arctan \mathrm{\&alpha;}}\&CenterDot;c_{w1}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w1}\left(x\right)=x\&CenterDot;\arctan x-\frac{\ln (1+x^2)}{2},$ X is function c _w1(x) independent variable;

The time-domain expression of Asinh Chirp pulse is:

$\begin{array}{c}{p}_{w2}\left(t\right)=G\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{il}\left(1\right)}t+\frac{T_{\mathrm{fra}\left(1\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}\left(1\right)}-f_l}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left(\mathrm{\&beta;}\right))\\ +G_N\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(N\right)}t+\frac{T-T_{\mathrm{fra}\left(N\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_h-f_{\mathrm{ih}\left(N\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_N\right))\\ +\underset{j=1}{\overset{N-1}{\mathrm{\&Sigma;}}}{G}_j\left(t\right)\&CenterDot;\cos 2\mathrm{\&pi;}(f_{\mathrm{ih}\left(j\right)}t+\frac{T_{\mathrm{fra}(j+1)}-T_{\mathrm{fra}\left(j\right)}}{\mathrm{\&alpha;}}\&CenterDot;\frac{f_{\mathrm{il}(j+1)}-f_{\mathrm{ih}\left(j\right)}}{\mathrm{arcsinh}\mathrm{\&alpha;}}\&CenterDot;c_{w2}\left({\mathrm{\&gamma;}}_j\right))\end{array},$

Function wherein $c_{w2}\left(x\right)=x\&CenterDot;\mathrm{arcsinh}x-\sqrt{1+x^2}.$